Abstract The mass analysis of natural gas for the extraction and separation of the undesirable component such as sulfur dioxide is significant for industrial applications. In this research, numerical simulations are performed to investigate the capability of the Knudsen thermal force for the detection of sulfur dioxide in CH4/SO2 gas mixture. Recently, a new micro gas sensor (MIKRA) is introduced to apply this force for measurement of the pressure. In fact, this device operates due to temperature difference inside a rectangular enclosure with heat and cold arms at low pressure condition. In order to simulate a rarefied gas inside the micro gas detector, Boltzmann equations are applied to obtain high precision results. To solve these equations, Direct Simulation Monte Carlo (DSMC) approach is used as a robust method for the non-equilibrium flow field. This study has focused on the effect of various concentrations of the CH4/SO2 gas mixture and reveals the main mechanism of force generation inside the device. Our findings show that value of generated Knudsen force significantly changes when the fraction of SO2 in CH4/SO2 gas mixture is varied. This indicates that this micro gas sensor could precisely detect the concentration of sulfur dioxide gas inside a low-pressure CH4/SO2 gas mixture.

中文翻译：

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低压 MEMS 气体传感器对 CH4/SO2 气体混合物的质量分析

摘要 用于提取和分离二氧化硫等不良成分的天然气质量分析对于工业应用具有重要意义。在这项研究中，进行了数值模拟以研究 Knudsen 热力检测 CH4/SO2 气体混合物中二氧化硫的能力。最近，引入了一种新的微型气体传感器 (MIKRA) 来施加这种力来测量压力。事实上，该设备的运行是由于在低压条件下具有热臂和冷臂的矩形外壳内的温差。为了模拟微型气体探测器内部的稀薄气体，应用玻尔兹曼方程以获得高精度结果。为了解决这些方程，直接模拟蒙特卡罗 (DSMC) 方法被用作非平衡流场的稳健方法。这项研究侧重于不同浓度的 CH4/SO2 气体混合物的影响，并揭示了设备内部产生力的主要机制。我们的研究结果表明，当 CH4/SO2 气体混合物中 SO2 的比例变化时，所产生的 Knudsen 力的值会发生显着变化。这表明该微型气体传感器可以精确检测低压 CH4/SO2 气体混合物中二氧化硫气体的浓度。